Automatic control for cotton processing equipment



June 14, 1955 w. P. FREEMAN, JR I 2,710,455

AUTOMATIC CONTROL FOR COTTON PROCESSING EQUIPMENT.

Filed Aug. 20, 1951 s 3 A A 2 s 50 22 HOT 9/1? HND C0 Tron/ 26 8 fOVERFLOW HIE/T I2 /64 i STALL TOWER DEIER\ PRESSURE DIFFERENT/BL SWITCHAll? 4 53 4 C 17 ;r

34 COTTON DAMPER HNO 9/? FA N 40 SEPHRRTOR 5/6 L IN l/EN To 2 WILL IHMP. FREEMAN ,JR.

ATTQRA/E/S United States Patent 0 AUTOMATIC CONTROL FOR COTTONPROCESSING EQUIPMENT William P. Freeman, Jr., Dallas, Tex., assignor toJohn giisMitcllell Company, Dallas, Tex., a corporation of sounApplication August 20, 1951, Serial No. 242,685 2 Claims. (CI. 34-54)The present invention relates generally to the cleaning and processingof mechanically picked cotton, and more particularly to an automaticcontrol for controlling the cotton to catch in certain pieces of theequipment, and

particularly in the tower drier so as to stop the flow or" uncleanedcotton through the equipment. In the known constructions, there is noway of automaticallystopping the flow of cotton into the processingequipment when this type of trouble occurs, with the result that thecotton continues to pile up at the obstruction and clog the equipmentuntil it cannot take any more. The equipment then has to be shut down,and considerable time and money are spent in order to open the cloggedpassageways.

It is an object of the present invention, therefore, to provide a novelautomatic control for stopping the flow of cotton into the cleaningequipment when a stoppage occurs so as to prevent the cotton from pilingup against the obstruction. More particularly, it is an object toprovide a control which automatically cuts ofi the suction at the inletwhen the pressure differential between two selected positions in theequipment exceeds a predetermined normal amount so as to preventadditional cotton from being fed into the equipment.

Another object is to provide an automatic control which stops the flowof cotton into the equipment when a stoppage occurs and, at the sametime, energizes a warning device to indicate an abnormal condition inthe equipment.

Further objects and advantages of the present invention will be apparentfrom the detailed description, reference being had to the accompanyingdrawing wherein a preferrcdembodiment of the present invention is shown.

Broadly, the present invention comprises a suction pipe for conveyingthe cotton from the wagons and introducing it into the processingequipment, a damper for controlling the vacuum in the pipe, a pressureditierential switch connected to two different parts of the equipmentand constructed to become operative when the pressure difference betweenthe two parts rises above a predetermined normal value, and motor meansfor closing the damper when the pressure differential switch becomesoperative so as to stop the flow of cotton into the processingequipment. A signal, of either the visual or audible type, is alsoconnected to the pressure difierential switch so as to indicate when anabnormal condition exists in the equipment, and thereby warn theoperators.

In the drawing, the figure represents a top plan schematic view of aconventional cotton processing plant employing an automatic controlembodying the teachings of the present invention.

Referring to the drawing more particularly by reference numerals, 10indicates generally a conventional cotton processing plant provided withan automatic control constructed according to the teachings of thepresent invention and generally indicated by the numeral 11. Theprocessing plant includes a separator 12, a tower drier 14, a roughingextractor-cleaner machine 16, and a distributor 18, which is disposedover a plurality of gin stands 20. An overflow stall 22 is positioned atthe outlet end of the distributor 18 so as to catch the overflow from itwhen the cotton entering the distributor exceeds the amount which can behandled by the gin stands 20.

A suction pipe 24 is provided which is connected to one side of theseparator 12. This pipe contains an inlet portion 26 disposed in theoverflow stall 22, and inlet portions 23 and 30 positioned in the wagonyard so that they can be worked around in the wagons W by the operators.

A suction fan 32 is connected to the other side of the separator 12 bymeans of a pipe 34, and a damper valve 36 is contained in the pipe 34for controlling the flow of air through it. The damper valve 36 isnormally biased toward the open position and is closed by means of anelectric motor 38 which forms part of the automatic control 11. Themotor 38 is responsive to the how conditions in the equipment so as toclose the damper valve 36 and stop the introduction of cotton into theseparator when a stoppage occurs, as will be described more fullyhereinafter.

In the separator 12 there is an air seal dropper similar to that shownat 25, 26 in Mitchell Patent 1,942,868. A hot air supply pipe 40, andeduction pipe 42 are connected into the separator below the dropper sothat cotton from the dropper is blown by the hot air into pipe 42 whichconnects to the top of the tower drier 14. A pipe 44 leads from thebottom of the tower drier 14 and connects it with the inlet of theroughing extractor-cleaner machine 16, and the outlet of the roughingextractorcleaner machine 16 is connected to the inlet of the distributor18 by means of a pipe 46.

The control 11 for automatically controlling the flow of cotton into theprocessing equipment includes a pressure differential assembly 48, oneside of which is connected to the pipe 42 by a conduit Sti and the otherside of which is connected to the pipe 44 by a conduit 52. Thus, thepressure ditierential assembly 48 is connected between the inlet and theoutlet of the tower drier 14 so that it will respond to any increaseover a predetermined normal pressure difference between the inlet andthe outlet of the drier, as will occur when there is an obstruction init.

The pressure diiierential assembly 48 contains an electrical switchwhich has one side connected to one side of an electric power source 53by a conductor 54. The other side of the switch is connected by means ofa conductor 56 with one side of the motor 38, and the other side of themotor 38 is connected to the other side of the power source 53 by aconductor 58. Thus, when the switch in the pressure ditferentialassembly 48 is closed, the motor 38 is energized so as to move thedamper valve 38 to. the fully closed position and completely stop theflow of air to the suction fan 32.

An electrically operated signal 66 is located in the wagon yard in thevicinity of the operators working the suction inlets 28 and 39 so as towarn them when a stoppage has occurred. The signal 60 is connected inparallel with the conductors 56 and 58 by conductors 62 and 64,respectively, and is preferably of the audible and visible type,although it can be either audible or visible alone.

Operation During normal operation, the damper valve 36 is maintained inthe open position by the biasing means so that the suction fan 32 causesa vacuum at the ends of pipes 26, 28 and 30 which draws the uncleanedcotton from the overflow stall 22 and wagons W and causes it to enterinto the separator 12. In the separator 12, the uncleaned cotton isseparated from the air and drops downwardly through an air seal into areceiver (not shown) below the separator. The air passes out of theseparator, through the pipe 34 and past the damper valve 36, into thesuction fan 32.

Heated air enters the pipe and picks up the cotton from the receiverthat has dropped through the air seal below the separator and carries itthrough the pipe 42 into the top of the tower drier 14. The cotton thenpasses downwardly through the tower drier 14 and out through the pipe 44into the roughing extractor-cleaner machine 16. The cotton leaves theroughing machine and passes through a pipe 46 and into the distributor18 which distributes the cotton to the various gin stands 20 disposedbelow it. If the amount of cotton entering the distributor exceeds theamount that can be handled by the gin stands 20, the excess cottonpasses out of the outlet end of the distributor and falls into theoverflow stall 22.

When the cotton is flowing through the equipment, there is a normaldifference between the pressure in the pipe 42 at the top of the towerdrier 14 and the pressure in the pipe 44 at the bottom of the towerdrier 14. These two different pressures are transmitted to the pressuredifferential assembly 48 through the conduits 50 and 52, and as long asthe pressure difference between these two points in the system isnormal, the switch in the pressure differential assembly 48 remainsopen. However, when a stoppage occurs in the tower drier 14, the cottonwill pile up and form a barrier within the tower drier and cause asubstantial decrease in the fiow of air to the pipe 44. This will causea decrease in pressure in the conduit 52 and an increase in the pressurein the pipe 42 and the conduit 50. When this pressure exceeds the amountfor which the pressure differential assembly 48 has been set, the switchwill close and complete the electric circuit to the motor 38. Thecircuit is from one side of the power source 53, through the conductor54, the pressure differential assem bly 48, the conductor 56, the motor38, and the conductor 58 back to the other side of the power source 53.When the motor 38 is energized, it actuates the damper valve 36 so as tocause it to close the pipe 34, thereby destroying the vacuum in pipes 24and pipes 26, 28 and 30. This prevents additional cotton from beingsucked up into the separator and from being introduced into the airstream passing through the pipe 42, thereby preventing additional cottonfrom piling up on the obstruction and clogging the tower drier 14.

Although the pressure differential assembly is shown connected acrossthe tower drier, it is apparent that it can be connected across any partof the equipment where a stoppage is apt to occur.

Simultaneously with the completion of the electrical circuit through themotor 38 by means of the closing of the switch in the pressuredifferential assembly 48, a second circuit is completed through thesignal 60 so as to inform the operators in the wagon yard that astoppage has occurred. The circuit to the signal device 60 is made fromone side of the power source 53 through the conductor 54, the switch inthe pressure differential assembly 48, the conductor 56, the conductor62, the signal device 60, the conductor 64, and the conductor 58 back tothe other side of the power source 53.

Even though the vacuum is destroyed in the inlet pipe 24, the heated aircontinues to flow through the pipes 40 and 42 into the tower drier 14 sothat, in the event the obstruction frees itself, the pressure balance ornormal pressure differential between both sides of the tower drier willbe restored and cause the system to resume normal operation. Thus, whenthe pressure difference returns to normal, the switch in the pressuredifferential assembly 48 will open, thereby opening the circuit to themotor 38.

This permits the biasing means to return the damper valve 36 to thefully open position, thereby restoring the vacuum in the pipe 24. Assoon as the vacuum is restored in the pipe 24 and its branches 26, 28and 30, the flow of cotton from the overflow stall 22 and the wagons Wwill resume. If the operators are not at the wagons when the vacuum isrestored, the deenergization of the signal device 60 caused by theopening of the switch in the pressure differential assembly 48 willindicate that operation has returned to normal so that they can resumethe feeding of the cotton into the pipes 28 and 30.

Thus, it is apparent that there has been provided a novel automaticcontrol which fulfills all of the objects and advantages soughttherefor. As soon as a stoppage occurs in that part of the equipmentbetween the conduits 50 and 52, the increase of the pressuredifferential above normal will stop the flow of additional cotton intothe equipment, thereby preventing it from piling up against theobstruction. At the same time, it will cause the energization of asignal to indicate to the operators in the wagon yard, and elsewhere ifdesirable, that a stoppage has occurred.

It is to be understood that the foregoing description and theaccompanying drawing have been given only by way of illustration andexample, and that changes and alterations in the present disclosure,which will be readily apparent to one skilled in the art, arecontemplated as within the scope of the present invention, which islimited only by the claims which follow.

What is claimed is:

l. A device of the type described, comprising means for processing rawcotton; means for causing air to flow through the processing means forcarrying the cotton therethrough; separate means for introducing rawcotton into the air stream flowing through the processing meansincluding a suction fan, a pipe connected to the suction fan, and adamper valve in the pipe for controlling the flow of air to the suctionfan, said suction means being air sealed from said air flow causingmeans; a pressure differential switch connected to different parts ofthe processing means which have a predetermined pressure differential onnormal operation of the processing means, the switch becoming operativewhen the pressure differential increases a predetermined amount abovenormal; and means operatively connected to said switch for actuating thedamper valve to stop the flow of air to the suction fan upon operationof the pressure differential switch.

2. A device of the type described, comprising means for processing rawcotton including a tower drier; means for causing air to flow throughthe processing means for carrying the cotton therethrough; means forintroducing raw cotton into the air stream including a suction fan, apipe connected to the inlet of the suction fan, a damper valve in thepipe, and an electric motor for operating the damper valve; a pressuredifferential switch connected to the inlet and the outlet of the towerdrier, the switch being closed when the pressure difference between thetower drier inlet and its outlet exceeds a predetermined amount; andelectrical connections between the switch and the motor for energizingthe latter when the switch closes so as to cause the damper valve toclose and stop the passage of air to the exhaust fan.

References Cited in the file of this patent UNITED STATES PATENTS1,365,804 Strong Jan. 18, 1921 1,942,868 Mitchell Ian. 9, 1934 1,962,320Mitchell June 12, 1934 2,060,305 Hagler Nov. 10, 1936 2,189,099 BennettFeb. 6, 1940 2,403,976 Harvey July 16, 1946 2,404,937 Anderson July 30,1946 2,419,436 Boho Apr. 29, 1947 2,525,535 Erisman et al. Oct. 10, 1950

1. A DEVICE OF THE TYPE DESCRIBED, COMPRISING MEANS FOR PROCESSING RAWCOTTON; MEANS FOR CARRYING AIR TO FLOW THROUGH THE PROCESSING MEANS FORCARRYING THE COTTON THERETHROUGH; SEPARATE MEANS FOR INTRODUCING RAWCOTTON INTO THE AIR STREAM FLOWING THROUGH THE PROCESSING MEANSINCLUDING A SUCTION FAN, A PIPE CONNECTED TO THE SUCTION FAN, AND ADAMPER VALVE IN THE PIPE FOR CONTROLLING THE FLOW OF AIR TO THE SUCTIONFAN, SAID SUCTION MEANS BEING AIR SEALED FROM SAID AIR FLOW CAUSINGMEANS; A PRESSURE DIFFERENTIAL SWITCH CONNECTED TO DIFFERENT PARTS OFTHE PROCESSING MEANS WHICH HAVE A PREDETERMINED PRESSURE DIFFERENTIAL ONNORMAL OPERATION OF THE PROCESSING MEANS, THE SWITCH BECOMING OPERATIVEWHEN THE PRESSURE DIFFERENTIAL INCREASES A PREDETERMINED AMOUNT ABOVENORMAL; AND MEANS OPERATIVELY CONNECTED TO SAID SWITCH FOR ACTUATING THEDAMPER VALVE TO STOP THE FLOW OF AIR TO THE POSITION FAN UPON OPERATIONOF THE PRESSURE DIFFERENTIAL SWITCH.